Of the two devices, we ordered from their crowdfunding campaign, only one arrived so far. The app ist very basic and the device itself quite bulky compared to others currently available on the market. The charger design isn't working as well as expected since the device is coupled very loosely and easily disconnects and stops charging.
All in all, it did sound like a good idea at the time, but that time passed two years ago while everyone in the market released multiple iterations of devices with similar functionality for less money. The current version of the angel is too little (or too much bulkyness) too late for far too much money.

@wade unfortunately, this sounds good on paper, but in reality the unit is badly designed. As someone who's backed 100+ projects on crowdfunding platforms, most of them tech-related, I've seen my share of bad design. This one definitely places on the top 5 list: the charging station is proprietary and designed in a way that isn't compatible with physics and gravity (it falls out of the charger). It's hard to put on even for someone who has full mobility and function in both hands, due to the very badly designed clasp. I have yet to try the app, but if the actual design of the product is any indication, then the app won't give you any valuable insights or data.